Panayides, P., M. Gavrielides, C. Galatopoulos, and M. Gavriilidou. “Using Rasch Measurement to Create a Quality of Sleep Scale for a Non-Clinical Sample Based on the Pittsburgh Sleep Quality Index (PSQI)”. Europe’s Journal of Psychology, Vol. 9, no. 1, Feb. 2013, pp. 113-35, doi:10.5964/ejop.v9i1.552.